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Largo
Sport climber
The Big Wide Open Face
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Jul 16, 2010 - 08:47pm PT
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From all of this conspiracy talk, what is the "unofficial" explanation on 9/11, who were the conspirators (speculate, will you), and who stood to profit form it?
JL
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 09:43pm PT
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JL, I'd tell you but then they would have to kill me.
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Jennie
Trad climber
Elk Creek, Idaho
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Jul 16, 2010 - 09:50pm PT
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So it's been officially determined the physics of falling pennies have no relevance to high dollar building collapses? (I knew it all along)
Questions: given the unsupported perimeter columns came down in tall pieces,
Why were most of the steel plates which hold the floors up, especially those from near the bottom, stripped off? Wouldn't that suggest the tremendous weight and momentum stripped them off as the floors "pancaked" on their way down. (I understood that in most planned demolitions, it's the BOTTOM of the structure that is forced out of alignment and the upper portion fall and crumble onto the demolished remains of the lower building.)
If there was a conspiracy to destroy the towers by planned pyro demolition, why not do it in a conventional and much, much less complicated manner...from the bottom? Hadn't terrorists already attempted bringing down the towers with explosions in the basement?
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 09:58pm PT
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There were explosions in the basement and lower floors. Read the eye witness testimonies of the professional 911 responders.
There is NO WAY on this earth that those buildings fell as they did and as fast as they did ecause of a plane strike and fire. NO WAY. The damage was done in a split moment the fires expended thee fuel source within minutes yet the buildings stood for an extended period of time before poof free fall speed.
Wake up dummies.
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Jennie
Trad climber
Elk Creek, Idaho
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Jul 16, 2010 - 10:05pm PT
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But the towers clearly demolished from the upper stories down.People were
entering and leaving at the bottom until the upper levels came down.
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 10:08pm PT
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I think you may want to look analytically at the high speed film of the three buildings falling before you make such a determinate assertion (assumption).
Credible witnesses and reliable richter readings clearly indicate additional large explosions unrelated to the plane crashes.
You have been and are being duped. And you should be outraged.
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rrrADAM
Trad climber
LBMF
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Jul 16, 2010 - 10:08pm PT
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rrrAdam - "Back at you...
He said the net force is up, meaning, he is saying that after he adds the two forces together (static load of the floor below [the up force], with the dynamic load of 30 stories falling 10+ feet [the down force]), that the up force is greater, thus it is the net force. This is simply absurd. "
Really?
The net force is upwards PERIOD. Otherwise the building would never stand.
What that means is that the strenght of floor 95 has to be equal of greater than the force of the 15 floors above it. Meaning the net force is upwards. Otherwise, if I built a building, and say floor 10, had 200tons of "Dead Load" (Meaning no human or dynamic forces applied, just the structure itself), that it had to hold. If I designed that floor to only hold 199tons it would fail. If I designed it to hold 200tons, and then had people in it, computers, wind, etc. It would fail. Do you understand that.
So he accurately, then explains it. That becuase of the net "upward force" of the structure, the one that hasn't allowed it to fall in 30+ years. The falling block meets resistance.
For the what, 10th time(?), NOT when a dynamic load such as 30 stories falling is involved.
As designed [static], the net foprce is up, that's why it stands... When a dynamic load above (down) exceeds the designed static load, the net force is down.
Same goes for the pro... If your piece will hold 2 times body weight, that is a static load, but iof you dynamicly load it with greater than 2 times body weight, it will fail, as the net load is down.
Why am I trying... TYou don't even know what the word "melt" means:
mimi "The steel did sag due to the heat. If this meets the definition of 'heat of fusion' then some of the beams 'melted.' Is that so wrong? "
Thank you!
Do you know what the "melting temperature" of steel is? Now what happens when it reaches this temperature? It undergoes a 'phase transistion', and turns from a solid into a ___. Can you fill in the blank?
The temps got nowhere near this. The joists did NOT 'melt', they were weakened by the heat. Why don't you do a little research and look and see at what temp carbon steel loses half of it's strength. You will notice that this is well below it's "melting" temperature.
Thus, the steel didn't melt, which is basically the same thing as 'heat of fusion'. You should know this, as an engineer. Unless of course, you are an engineer like Casey Jones.
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 10:11pm PT
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Sorry but kerosene does not burn hot enough to melt or even significantly soften steel.
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rrrADAM
Trad climber
LBMF
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Jul 16, 2010 - 10:16pm PT
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If the guy is wrong, I would like to know why, so I can stop making an ass of myself.
We are trying to tell you, but you will not listen.
THE NET FORCE IS NOT UPWARD IN A DYNAMIC SITUATION LIKE THAT!!!!!!!!!!!111111111111eleven
It is down, in order of magnatude.
He is wrong.
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Jennie
Trad climber
Elk Creek, Idaho
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Jul 16, 2010 - 10:18pm PT
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There is NO WAY on this earth that those buildings fell as they did and as fast as they did ecause of a plane strike and fire. NO WAY. The damage was done in a split moment the fires expended thee fuel source within minutes yet the buildings stood for an extended period of time before poof free fall speed.
Wake up dummies.
This dummy would appreciate knowing why the 83rd floor progressively sagged through the 51 minutes....... if the heat was quickly dissipated. Steel distorts and bends well below melting temperature.
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rrrADAM
Trad climber
LBMF
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Jul 16, 2010 - 10:21pm PT
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Sorry but kerosene does not burn hot enough to melt or even significantly soften steel. Says who?
I can significantly soften a steel coat hanger in a campfire, and that doesn't have the significant air flow that all the broken windows of the WTC provided.
Now before some moron wants to say "it wasn't a windy day", it doesn't have to be... Broken windows above and below the fires allows for convection to draw air in from below the fires and be expelled above them.
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 10:25pm PT
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Are you really equating a coat hangar with structural steel?
And I suppose the jet fuel aka kerosene burning at the pentagon got hot enough to melt the several tons of titanium comprising the missing jet engines.
Wow physics, chemistry and mathematics just don't hold a candle to blind faith.
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rrrADAM
Trad climber
LBMF
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Jul 16, 2010 - 10:27pm PT
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There were explosions in the basement and lower floors. Read the eye witness testimonies of the professional 911 responders.
There is NO WAY on this earth that those buildings fell as they did and as fast as they did ecause of a plane strike and fire. NO WAY. The damage was done in a split moment the fires expended thee fuel source within minutes yet the buildings stood for an extended period of time before poof free fall speed.
Wake up dummies. Are you Rosie O'Donnell? You sound like here.
It's OK, you can tell us. You are, aren't you.
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 10:28pm PT
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Wake up Dummy.
Ooooh I can soften a coat hangar in my camp fire. Hahahahahahaha!
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rrrADAM
Trad climber
LBMF
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Jul 16, 2010 - 10:31pm PT
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Are you really equating a coat hangar with structural steel? They were your words, dummy. You said steel.
So, what is the difference between structural steel and a steel coat hanger (other than mass), as far as it's melting point, or even the point at which it becomes ductile or maliable? There are minuite differences in what it may be alloyed with, but this has little effect, as structural steel is mainly just plain old carbon steel.
What you said is just plain wrong. Admit it.
I don't think you can, Rosie.
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monolith
climber
Berkeley, CA
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Jul 16, 2010 - 10:34pm PT
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Ah, but the contents of the building burning will weaken steel.
The av gas was consumed quickly.
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philo
Trad climber
Somewhere halfway over the rainbow
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Jul 16, 2010 - 10:36pm PT
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OMG dude. You know so little about art and science of metallurgy and yet you want to sound so informative.
And Mono nothing in that building could have gotten hot enough even if the insignificant fires burned for a week.
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Tony Bird
climber
Northridge, CA
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Jul 16, 2010 - 10:38pm PT
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everyone who's onto this is trying to figure that out, john. we don't exactly have subpoena power and search warrants for the pentagon and the white house, but most of us think there is enough serious evidence to justify it.
as we've mentioned previously, such a hoaxed attack is not without precedent. the maine, the lusitania, and pearl harbor are all under suspicion as spectacular events that brought the nation into war. many believe that fdr provoked the japanese and then allowed pearl harbor to be attacked for this purpose. evidence is controversial on all of these, but operation northwoods is not since it was recently made public record. this plan made it all the way to president kennedy, endorsed by admiral lemnitzer, chairman of the joint chiefs of staff, and robert mcnamara, secretary of defense. it called for hijackings and bombings--sound familiar?--to be performed on american citizens and military and blamed on cuba to gain public sentiment for invading cuba. people don't want war. they have to be goaded into it.
if you read the PNAC document--project for a new american century--it will tell you about some of the people and the thinking suspected to have been involved in the 9/11 operation. these neocons went so far as to call for "a new pearl harbor" to galvanize public approval for the big opportunity we had to go out and dominate a world in which the failure of communism eliminated our main antagonist. which is exactly what happened in the wake of 9/11, pushed to the hilt with lies about things like WMDs. profit? check halliburton's balance sheet.
beyond all that, it tends to get weird. there's the shadowy "bilderburg group" of powerful political leaders and business figures that meets annually in a top secret retreat. some blame israel, some see involvement of the vatican and/or the jesuits and certain euro royalty like queen elizabeth of england, queen beatrix of holland and king juan carlos of spain. there are reports of an illuminati network, the involvement of certain high levels of the masonic order, and from there it goes to lizard men and space aliens--i'm not joking.
you want the dirty laundry, that about covers it. i just want subpoena power in the hands of someone who doesn't have a ring through his nose, and that's a very tall order.
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Jennie
Trad climber
Elk Creek, Idaho
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Jul 16, 2010 - 10:40pm PT
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From: http://www.tms.org/pubs/journals/jom/0112/eagar/eagar-0112.html
It is known that STRUCURAL STEEL begins to soften around 425°C and loses about half of its strength at 650°C.4 This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.
The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box columns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150°C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which resulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.
Nearly every large building has a redundant design that allows for loss of one primary structural member, such as a column. However, when multiple members fail, the shifting loads eventually overstress the adjacent members and the collapse occurs like a row of dominoes falling down.
The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures. Many structural engineers believe that the weak points—the limiting factors on design allowables—were the angle clips that held the floor joists between the columns on the perimeter wall and the core structure (see Figure 5). With a 700 Pa floor design allowable, each floor should have been able to support approximately 1,300 t beyond its own weight. The total weight of each tower was about 500,000 t.
As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour. If it had been free fall, with no restraint, the collapse would have only taken eight seconds and would have impacted at 300 km/h.1 It has been suggested that it was fortunate that the WTC did not tip over onto other buildings surrounding the area. There are several points that should be made. First, the building is not solid; it is 95 percent air and, hence, can implode onto itself. Second, there is no lateral load, even the impact of a speeding aircraft, which is sufficient to move the center of gravity one hundred feet to the side such that it is not within the base footprint of the structure. Third, given the near free-fall collapse, there was insufficient time for portions to attain significant lateral velocity. To summarize all of these points, a 500,000 t structure has too much inertia to fall in any direction other than nearly straight down.
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monolith
climber
Berkeley, CA
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Jul 16, 2010 - 10:41pm PT
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You are hilarious Philo.
Modern office building fires can read 1800f. Steel loses 90% of its strength at those temps.
Why the heck do you think steel needs to be insulated in a highrise?
Edit: yea what Jennie posted. But of course all those engineers are in on it cuz they don't want to lose their jobs.
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